Warning: this is irrelevant to the stated charter of NANOG. Hit "D" now. I mean it. Don't read this. It's not about network operations.
This not just true for UNIX, a good friend of mine works out at Microsoft on the NT development team. He claims they've been seeing similar numbers on Alpha and Pentium Pro machines under Windows NT.
My experience differs significantly, but then my P/Pro is 200MHz and my Alpha is 333MHz. Microsoft probably has older Alphas and newer P/Pro's. Any of you installing Sun or Intel machines for netnews or shell or file service or anything else requiring good source code compatibility (barring 32-bit pointer assumptions such as those in the route servers) and large numbers of computrons are being silly. DEC would loan you an Alpha for a month to prove you wrong, since they know you won't be able to live without it and the chance of them having to take it back is small.